Japanese Patent Application No. 2001-101516, filed on Mar. 30, 2001, is hereby incorporated by reference in its entirety.
The present invention relates to a surface emission type semiconductor light-emitting device such as a surface emission type semiconductor laser or light emitting diode, and a method of manufacture thereof.
For example, in a surface emission type semiconductor laser, it is known to have a columnar portion constituting a resonator and embedded on its periphery in a resin material such as polyimide or the like. However, when an embedding insulation layer of such a resin material is used, when the wafer on which the light-emitting element is formed is separated, the following problems may occur. Specifically, since the embedding insulation layer formed of the resin material has a higher plasticity than the semiconductor layer and is harder to cut, it is difficult to prevent cleavage of the semiconductor layer and accurately separate the wafer by scribe. For the same reason, when the wafer is separated by dicing, external force applied to the embedding insulation layer may adversely affect the light-emitting element. If in this way the wafer cannot be satisfactorily separated, this may lead to problems such as particle emission, die attach and die bonding defects, chip damage, and so on.
The present invention may provide a method of manufacturing a semiconductor light-emitting device using a resin material as an embedding insulation layer, in which wafer separation can be carried out reliably and easily, and the semiconductor light-emitting device.
The method of manufacturing a semiconductor light-emitting device according to one aspect of the present invention comprises:
a step of forming a stacked semiconductor layer having a plurality of columnar portions over a semiconductor substrate;
a step of forming an embedding insulation layer of a resin material around each of the columnar portions; and
a step of separating the semiconductor substrate and layers on the semiconductor substrate to form chips, wherein in the step of forming the stacked semiconductor layer having the columnar portions, a separating semiconductor layer of a given pattern is formed in boundary regions of the chips,
wherein in the step of forming the embedding insulation layer, at least an upper surface of the separating semiconductor layer is exposed, and
wherein in the step of forming the chips, the separation is carried out using the separating semiconductor layer.
According to the manufacturing method of the present invention, by using the separating semiconductor layer, the separation of the wafer (the semiconductor substrate and the layers formed on the substrate) can be carried out reliably and easily.
The method of this aspect may have the following features.
(a) The columnar portions and the separating semiconductor layer may be patterned by lithography and etching after forming the stacked semiconductor layer on the semiconductor substrate.
(b) A step of forming an electrode layer in a given pattern may be included after the step of forming the embedding insulation layer. An end of the electrode layer may be formed away from the separating semiconductor layer.
(c) The separating semiconductor layer may have the following structures.
The separating semiconductor layer may be continuously formed in the boundary regions of the chips, and the separation of a wafer maybe carried out along the separating semiconductor layer.
The separating semiconductor layer may be discontinuously formed in the boundary regions of the chips, and the separation of a wafer may be carried out along the separating semiconductor layer.
Furthermore, two of the separating semiconductor layers may be formed with a given spacing in the boundary regions of the chips, and the separation of a wafer may be carried out between the two separating semiconductor layers. Between the two separating semiconductor layers, an insulation layer may be formed in the step of forming the embedding insulation layer.
(d) The separating semiconductor layer may have a reinforcing portion formed in an intersecting region thereof. The reinforcing portion may be formed of a semiconductor layer formed at a corner of the separating semiconductor layer. The reinforcing portion may be formed of an insulation layer formed in an intersecting region of the separating semiconductor layer, and the insulation layer may be formed in the step of forming the embedding insulation layer.
The semiconductor light-emitting device according to another aspect of the present invention has the following structure, reflecting the above manufacturing method. Specifically, this aspect of the present invention relates to a surface emission type semiconductor light-emitting device which emits light in a direction perpendicular to a semiconductor substrate, the semiconductor light-emitting device comprising:
a stacked semiconductor layer formed over a semiconductor substrate, and having a columnar portion;
an embedding insulation layer of a resin material formed around the columnar portion;
an electrode layer formed on at least a part of an upper surface of the columnar portion and a part of an upper surface of the embedding insulation layer; and
a separating semiconductor layer formed above an edge region of the semiconductor substrate.
The following features may be applied to the semiconductor light-emitting device of this aspect of the present invention.
The separating semiconductor layer may be formed in the step of forming the columnar portion of the stacked semiconductor layer and may have the same stacked structure as the columnar portion.
An end of the electrode layer may be formed away from the separating semiconductor layer. By means of this structure, electrical isolation of the electrode layer and the semiconductor substrate can be achieved.
The separating semiconductor layer may be continuously formed above the edge region of the semiconductor substrate. The separating semiconductor layer may be discontinuously formed above the edge region of the semiconductor substrate. Furthermore, an insulation layer may be formed above the edge regions of the semiconductor substrate, and the separating semiconductor layer may be located inside the insulation layer.
The separating semiconductor layer may have a reinforcing portion formed in an intersecting region thereof. The reinforcing portion may be formed of a semiconductor layer formed at a corner of the separating semiconductor layer. The reinforcing portion may be formed of an insulation layer formed in an intersecting region of the separating semiconductor layer, and the insulation layer may have the same layer construction as the embedding insulation layer.
The semiconductor light-emitting device of the present invention may be applied to a surface emission type semiconductor laser or a surface emission type light emitting diode, or the like.